Hermione squashed this plan by pointing out that, in the unlikely event that Harry managed to learn how to operate an Aqua-Lung within the set limit of an hour, he was sure to be disqualified for breaking the International Code of Wizarding Secrecy - it was too much to hope that no Muggles would spot an Aqua-Lung zooming across the countryside to Hogwarts.

A complete inventory meant that every nut and bolt, every butlet and firing pin, every Aqua-Lung and Emerson breathing apparatus was going to be enumerated, along with every index card, paper clip, and notepad.

Indeed, Cousteau brought the undersea world to millions through books and films, and also helped thousands to enjoy the undersea world themselves as the co-inventor of the Aqua-Lung, which was the precursor to modern scuba diving equipment.